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What is an excitation signal?
An excitation signal is a signal used to stimulate a system or device. It can be a physical input, such as an electrical voltage or current, which is applied to a system to produce a desired response or output. Excitation signals are commonly used in various fields such as control systems, signal processing, and communications.
What is the quantum relativity theory in as simple of terms as possible?
The merger of quantum mechanics with the special theory of relativity is commonly known as quantum field theory. According to this theory every particle of matter is just an excitation of a field that is everywhere in space. There is a different field for every different particle (this is not really true, but close enough). You might already be familiar with electromagnetism. In that theory (which has now been completely absorbed into quantum field theory) electric and magnetic forces are transmitted via photons. These photons are just excitations of the photon field. A photon has no mass, but all particles can be thought as as being excitations of fields. There is for example an electron field, but also a neutrino field and a muon field.
Revolving field theory of single phase induction motors?
The revolving field theory of single-phase induction motors suggests that a rotating magnetic field created by current flowing through two windings (main and auxiliary or starting winding) produces a starting torque in the rotor. This theory explains how single-phase motors can operate without the need for a separate rotating magnetic field, as in three-phase motors, by using a split-phase or capacitor start design to generate a rotating magnetic field.
What is the unit of measure for magnetic induction?
One of the most common electrical motor used in most applications which is known as induction motor. This motor is also called as asynchronous motor because it runs at a speed less than synchronous speed. In this, we need to define what is synchronous speed. Synchronous speed is the speed of rotation of the magnetic field in a rotary machine and it depends upon the frequency and number poles of the machine. An induction motor always runs at a speed less than synchronous speed because the rotating magnetic field which is produced in the stator will generate flux in the rotor which will make the rotor to rotate, but due to the lagging of flux current in the rotor with flux current in the stator, the rotor will never reach to its rotating magnetic field speed i.e. the synchronous speed.
What statements describes the result of reversing the current in a current-carrying in a magnetic field?
When the current is reverted, the magnetic field will also be reverted.
Does a induction motor need excitation?
The induction motor is the special kind of motor which runs below and above the synchronous speed. which the synchronous motor runs nearly equal the synchronous speed. The operation of synchronous motor runs with dc field excited hence separate dc field current is given to the field circuit. where as the induction motor the field and main field is drawn from the same supply hence no excitation is required. But due to this separate starting mechanism has to be required in case of the single phase induction motor.
Difference between static excitation system?
It is called static excitation when you make use of solid state components like diode and thyristors to convert to pure dc and to use this dc for field excitation of synchronous generators. The field winding of synchronous generators can be excited by dc source only. It is called brushless excitation because use of carbon brushes are not made here.It is called dynamic excitation is when you make use of rotating brushes. Excitation is necessary to produce reactive power and also to regulate the voltage of synchronous generators.
What is meant by excitation of synchronous machines?
Excitation of synchronous machines refers to the process of supplying direct current (DC) to the rotor winding to create a magnetic field, which is essential for the operation of the machine. This magnetic field interacts with the rotating magnetic field produced by the stator, enabling the machine to generate or synchronize with the grid frequency. Proper excitation is crucial for maintaining voltage levels and ensuring stable operation under varying load conditions. Inadequate or excessive excitation can lead to issues such as voltage instability or oscillations.
What is over excitation of field windings?
Over-excitation of field windings refers to a condition in synchronous machines, such as generators, where the field current exceeds the rated value, leading to an excessive magnetic field. This can result in increased voltage output and potential overheating of the machine. Prolonged over-excitation can damage the windings and other components due to overheating and insulation breakdown. It is critical to monitor and control the excitation levels to maintain safe and efficient operation.
What is synchronous impedance?
Synchronous impedance is also known as the EMF method. It is a ratio of open circuits to short circuits, when they both are referred to the same field excitation.
What is the electrical term excitation mean?
Excitation is normally used to describe the current supplied to the field winding of a motor. A motor has a rotating armature with a coil that rotates in the magnetic field produced by a fixed field coil. The current in the field coil can be taken from a series or parallel connection to the armature coil, or (usually for larger motors) it can be supplied independently via some sort of controller. Excitation can be used to control the speed of DC motors or the power factor of synchronous motors.
What is transformer turns ratio excitation current?
This is the current level needed to energize a transformer to its rated voltageThe clue is in the name! 'Excitation' means to create a magnetic field. So the excitation current is the current drawn from the supply which sets up the magnetic field around the core.
What is excitation and why is it needed for start up in an AC generator?
An alternator is just another name for a synchronous generator. Excitation is needed to create a magnetic field in the rotor. When to rotor is spun with excitation the magnetic field will cut through the stator field and produce an AC voltage in the stator field. In terms of an alternator with built in rectifier the stators AC voltage in the rectified to DC. The strength of excitation will determine the alternators output voltage. The AVR Automatic Voltage Regulator built into almost every alternator controls field current to maintain a constant output voltage.
When does synchronous motor get over exited?
A synchronous motor becomes over-excited when the excitation level exceeds the synchronous reactance of the motor, resulting in a leading power factor. This condition typically occurs when the field current supplied to the rotor is increased beyond the rated value, causing the motor to generate excess reactive power. Over-excitation can lead to higher voltage levels and potential damage to the motor and connected equipment if not managed properly. It is important to monitor and control the excitation to maintain optimal performance and prevent overheating or other operational issues.
What is exciter in electrical?
An exciter in electrical engineering refers to a device that provides the necessary excitation current to the field winding of a synchronous machine, such as a generator. This excitation current is essential for establishing the magnetic field required for the generator to produce electrical power. Exciters can be either rotating (mounted on the same shaft as the generator) or static (using solid-state technology), and they play a critical role in regulating the output voltage and stability of the generator.
Why is dc current used in the excitation of generator?
The field current is used for the excitation of generators.AnswerYou use DC current, because you want the resulting magnetic field to be constant. If you used AC, the resulting magnetic field would vary in both strength and direction.
What is meant by static excitation?
Static excitation refers to a method of supplying direct current (DC) to the rotor windings of a synchronous machine, such as a generator, to establish a magnetic field. This excitation is "static" because it typically involves the use of a stationary power source, like a rectifier, to convert AC voltage from the generator into DC. The static excitation system allows for precise control of the machine's output voltage and reactive power, enhancing stability and performance. It contrasts with dynamic excitation systems, which use rotating equipment to provide excitation.
